(a) Technical Field of the Invention
The present invention is related to a bulb with sensing function, and more particularly to one adapted with an infrared sensor to control on and off of the bulb for energy saving purpose.
(b) Description of the Prior Art
Advanced technology and discoveries of the principles of infrared help the development of more and more infrared-based products. When a bulb is adapted with an infrared sensor to detect the heat radiation, it achieves the practical and energy saving purpose. The bulb adapted with infrared sensor has been very popular in an age of surging awareness of environmental protection.
The bulb with sensing function of the prior art has an infrared sensor as the power switch of the light source of the bulb. When anyone enters into the range of the sensor, the sensor detects the heat emitted from the human body and turns on the bulb. When that person is out of the sensing range or motionless, the sensor controls the internal circuit to cut off the power supply to the bulb for saving energy. However, the bulb itself generates heat when turned on to confuse the infrared sensor. Therefore, the sensor and the bulb must be separately provided as taught in Publication No. 271806 (Taiwan Gazette) of a patent application titled “Burglarproof and Easy Assembly Lamp Holder”. Nonetheless, the separation of the bulb and the sensor prevents the installation of a shade to the bulb since the shade would block the detection of the movement outside the shade to compromise the working range of the sensor.